Generally, water is sprayed in a living room or a storehouse in a fine particle state which may be easily evaporated, for humidification. However, in case of an indoor space, even though water is supplied in a fine particle state, since the water is in a liquid state, the humidification effect is applied only to a region close to the spot where the water is sprayed. In addition, a low-temperature storehouse for storing agricultural products includes a cooling unit for lowering an internal temperature, and the cooling unit lowers the internal temperature by an evaporator so that water particles are adhered to the surface of the evaporator installed in the storehouse to create an ice layer. At this time, the moisture in the storehouse decreases as much as the amount of created ice, thereby lowering the relative humidity in the storehouse to the level of 65% to 85%. Accordingly, as the humidity in the low-temperature storehouse is lowered, the moisture contained in the agricultural products is evaporated in the air of the storehouse, thereby reducing the weight of the agricultural products. If agricultural products such as fruits and vegetables lose moisture, the moisture is evaporated from the agricultural products to reduce the weight of the agricultural products, and if the moisture is excessively evaporated, the skin of the agricultural products gets dry to deteriorate the appearance and thus lose marketing value. If the moisture loss becomes 5% or above, most agricultural products lose their marketing value, and their prices for farmers are also lowered due to quality deterioration. Meanwhile, crops such as ginger or sweet potato demand a high-humidity environmental condition of 90% to 98% during a curing or storing process after being harvested, and they are decayed if the humidity is low.
In order to solve such a problem, a heating humidifier, a centrifugal humidifier, or an ultrasonic humidifier is used to supply moisture. However, in case of the heating humidifier, even though moisture is supplied to the air in a vapor form, since the moisture has a high temperature, if the moisture is supplied to a low-temperature place, dew condensation occurs and the indoor temperature changes. Further, in case of the centrifugal and ultrasonic humidifiers, since air is humidified in a state where water is turned into particles, if the water particles are supplied to a low-temperature storehouse, dew condensation occurs at the wall of the storehouse or agricultural products in storage, and an amount of ice adhered to the evaporator increases. Therefore, while repeatedly performing a defrosting process, the temperature in the storehouse increases, and accordingly the temperature greatly changes in the storehouse, which makes it difficult to maintain the freshness of the agricultural products. Further, since both the centrifugal humidifier and the ultrasonic humidifier supply water to a storehouse in a water drop state at least minutely, even though the water is not frozen at the evaporator, if dew forms in the storehouse, the proliferation of mold or bacteria is promoted, thereby resultantly decaying the agricultural products.
In addition, in a workplace or laboratory which should maintain a sterilized state, if a sterilizing solution is sprayed, stains or spots created at walls, instruments or worktables should be removed. Moreover, since it is difficult to uniformly spray the sterilizing solution in the space of the laboratory, the sterilized state may not be easily maintained in the entire space of the laboratory.
Therefore, there is a recent need to develop a forced evaporative humidifier using nano-vapor which may humidify an indoor space with vapor, allow agricultural products to be stored while uniformly humidifies an inside of a storehouse at a relative humidity of 90% to 98% to prevent a moisture loss, and prevents dew condensation in the storehouse, and a sterilizing machine using nano-vapor which may uniformly supply a sterilizer to the entire space of a laboratory or the like without dew condensation.